This invention relates to electro-optical transducer systems employing a cathode ray tube and a deflection yoke and more particularly to means for relieving unwanted mounting stresses in the deflection yoke.
Deflection yokes are employed with cathode ray tubes in order to deflect an electron beam in a predetermined manner across the phosphor screen of the cathode ray tube. In the past it has been the practice to mount the deflection yoke within the signal receiver employed with the cathode ray tube by means of a complex jig arrangement which allowed the yoke to be moved in at least three directions in order to center the beam in an appropriate manner. Recently it has become the practice to adjust the yoke to the cathode ray tube at the tube manufacturing plant and then semi-permanently bond the yoke in a fixed position on the tube by means of a hardenable adhesive. It was with the latter form of yoke mounting that this invention is concerned.
It has been found that while the bonded yoke-cathode ray tube arrangement appears to be desirable, in practice it has been extremely difficult to maintain the semi-permanent type of bond required for practical purposes. In practice the seal between the yoke holding means and the tube has been found to fracture completely or to loosen sufficiently to destroy the critical beam alignment. Attempts to correct this problem by employing different adhesives have been found to be unsuccessful. It has recently been determined that part of the problem resides in the inherent stresses which develop throughout a yoke mounting system when the adhesive bonding method is used. Accordingly it is believed to be an advance in the art if a means could be found for obviating the above difficulties.